[VHFcontesting] TT Rotor Question

[Howard Reynolds]

A few days late with this.  I have two TT rotors, one at 80 feet with
144-1296 Yagis plus hi-vhf and uhf TV antennas on it, the other with a
Tri-bander and 6m yagi at 40 feet (see my QRZ page).  I climbed up the
short tower and noticed the hole for pinning the mast.  I have never done
so on either set-up and have never experienced slippage.  (Of course, these
aren't huge arrays.)  The saving grace may be that each mast is a 20 foot
steel galvanized pipe; about half above the thrust bearing and the other
half down to the rotor.  I'm sure during strong winds, the mast twists just
a little to absorb some of the torque on it without transferring all the
force to the rotor clamp.  On the other hand, I have seen one instance
where the rotor was mounted right under the thrust bearing and a 5-element,
15m Yagi just above it, i.e., only a few feet of mast.  The mast clamp held
but all of the rotor mounting bolts got sheared off.  So, I suppose the
moral is to mount the rotor way down in the tower with a long mast to soak
up a bit of the torque when the wind blows.  WA3EOQ